Method of producing coupled radical products

ABSTRACT

A method that produces coupled radical products from biomass. The method involves obtaining a lipid or carboxylic acid material from the biomass. This material may be a carboxylic acid, an ester of a carboxylic acid, a triglyceride of a carboxylic acid, or a metal salt of a carboxylic acid, or any other fatty acid derivative. This lipid material or carboxylic acid material is converted into an alkali metal salt. The alkali metal salt is then used in an anolyte as part of an electrolytic cell. The electrolytic cell may include an alkali ion conducting membrane (such as a NaSICON membrane). When the cell is operated, the alkali metal salt of the carboxylic acid decarboxylates and forms radicals. Such radicals are then bonded to other radicals, thereby producing a coupled radical product such as a hydrocarbon. The produced hydrocarbon may be, for example, saturated, unsaturated, branched, or unbranched, depending upon the starting material.

CROSS-REFERENCED RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/840,508 filed Jul. 21, 2010 (the '508 application). The '508application claimed the benefit of U.S. Provisional Patent ApplicationNo. 61/228,078, filed on Jul. 23, 2009 (the '078 application), U.S.Provisional Patent Application No. 61/258,557, filed on Nov. 5, 2009(the '557 application), and U.S. Provisional Patent Application No.61/260,961, filed on Nov. 13, 2009. The '508 application also claimedthe benefit of, and was a continuation application of, U.S. patentapplication Ser. No. 12/840,401 filed on Jul. 21, 2010, which claimedthe benefit of the '078 and '557 applications. These provisional andnon-provisional patent applications are expressly incorporated herein byreference.

BACKGROUND OF THE INVENTION

Hydrocarbon fuels are currently used throughout the world. One specificexample of a hydrocarbon fuel is gasoline (which includes octane).Another common hydrocarbon fuel is diesel fuel, which is used in dieselengines. Waxes, oils, and fuels are also desirable hydrocarbon products.Hydrocarbons are used in cosmetic and medical applications.

Biomass is a renewable feedstock. Biomass may comprise lipids (such asfats or oils) that are available from plant, algal, or animal origin.These fats or oils may include fatty acids. Obviously, given itsabundance in nature, it is desirable to find a way to use this biomassas a starting material to form a useable product, such as a hydrocarbonfuel.

Current methods to convert biomass to a hydrocarbon fuel involve theprocess known as “hydroreacting” in which hydrogen gas is added to thebiomass (in the presence of a catalyst) to convert the biomass tohydrocarbons. Unfortunately, hydroreacting is generally expensivebecause hydrogen gas is an expensive reactant. Also, a catalyst isinvolved in this process, and such catalysts are often intolerant withCa, Cl, V, N, As, Hg, Si, P, Cr or other materials that may be found inthe biomass. Other impurities include soluble vitamins, steroids,terpenes, alkaloids, etc. Another process to convert biomass tohydrocarbons is decarboxylation, wherein the carboxylic acidfunctionality of a fatty acid is “decarboxylated,” thereby leaving ahydrocarbon. (In some situations, this decarboxylation step may bepreceded by a fermentation step and/or a hydrolysis step, depending uponthe starting material.) Employing the decarboxylation process to producethe hydrocarbon is generally expensive.

Accordingly, there is a need for a new process by which biomass (such ascarboxylic acids, oils, etc.) may be converted into a hydrocarbon. Itwould be desirable for this process to be inexpensive to use and capableof producing a variety of different hydrocarbons. Such a process isdisclosed herein.

SUMMARY OF THE INVENTION

Biomass may be obtained from plant, animal, or algal materials and maybe comprised of a carbohydrates, lipids, lignins and the like. Biomassmay be converted into carboxylic acid, which may be a fatty acidmaterial (or other lipid material). Nonlimiting examples of carboxylicacids may include high-carbon carboxylic acids such as fatty acids (aCarbon content of C₁₂ or higher) or low-carbon carboxylic acids (aCarbon content of C₁₂ or lower). (“Low-carbon carboxylic acids” are alsoreferred to herein as a “carboxylic acid with a small number of carbonatoms.”) The carboxylic acids may be aliphatic carboxylic acids oraromatic carboxylic acids. The carboxylic acids may be monocarboxylicacids, dicarboxylic acids, or polycarboxylic acids, depending upon thenumber of COOH groups contained therein. As used herein throughout, theuse of “carboxylic acids” may mean any of the foregoing examples.Similarly, the use of any one of the foregoing examples may besubstituted if appropriate for any one of the other foregoing examples.Other embodiments may be designed in which the biomass is obtainedthrough one or more processing steps, before being converted into acarboxylic acid. Such steps may include isolating lipid materials or acarbohydrate material, or lignin material. Obtaining the biomass mayalso include extracting or converting biomass into lipid materials or acarbohydrate material, or lignin material. It will be appreciated bythose of skill in the art that the biomass may already be in the form ofa lipid, a carbohydrate, or lignin, fatty acids, or other forms and mayneed to be extracted, converted, isolated, and the like from thebiomass. Thus, the word “obtaining” as used herein throughout may or maynot include the steps of extracting, converting, isolating, and thelike. Examples of a lipid material include fatty acids, esters of fattyacids, triglycerides of fatty acids, fatty acid derivatives, and/ormetal salts of fatty acids. Examples of lignin material may includeresins. Examples of carbohydrate material may include cellulose,glucose, among many other examples.

Once this biomass material is obtained (from any source), this materialis converted to at least one alkali metal salt of a carboxylic acid.(Typically, this alkali metal salt is a sodium salt, however, otheralkali metal salts may also be used.) In some embodiments, conversion ofthe biomass or biomass material (collectively “biomass”) into the alkalimetal salt of carboxylic acid involves an intermediate step ofconversion into the carboxylic acid itself. Then, depending upon thesource of biomass, another conversion reaction may be needed to convertthe biomass into an alkali metal salt of carboxylic acid. The terms“alkali salt” and “alkali metal salt” are used interchangeablythroughout. For example, if the biomass is a lipid, the lipid may firstbe hydrolyzed into a carboxylic acid, which in this case may be a fattyacid, and then a “saponification” reaction using a base (such as sodiummethoxide or NaOH) is reacted with the carboxylic acid to form thealkali metal salt of carboxylic acid. Examples of saponificationreactions are shown below:

R—COOX+CH₃ONa→R—COONa+CH₃OH

R—COOX+NaOH→R—COONa+H₂O

In the above reactions, “X” is the remaining section of an ester, theremaining section of a triglyceride, hydrogen, or a metal other than analkali metal. The “R” represents the (carboxylic acid) chain of thelipid material. In embodiments where the biomass is a carbohydrate or alignin, or some other type of biomass, one or more differentintermediate steps may be needed to convert the biomass into an alkalimetal salt of carboxylic acid. For example, it may be that the biomassis fermented into the alkali metal salt of carboxylic acid. In otherembodiments, the biomass may be fermented into the carboxylic acid andthen saponified as described above to from the alkali metal salt ofcarboxylic acid. It will be appreciated by those of skill in the artthat after the conversion steps, if the starting biomass was a lipid,the resulting alkali metal salt of a carboxylic acid may be in the formof an alkali metal salt of a fatty acid. Similarly, where the startingbiomass is a carbohydrate, the resulting alkali metal salt of acarboxylic acid may be in the form of an alkali metal salt of alow-carbon carboxylic acid. Likewise, where the starting biomass is alignin, the resulting alkali metal salt of a carboxylic acid may be inthe form of an aromatic carboxylic acid alkali metal salt.

In some embodiments, one more of the intermediate steps are omitted andthe biomass is converted directly into at least one alkali metal salt ofa carboxylic acid by reacting a base with a quantity of the biomassitself to produce the at least one alkali metal salt of the carboxylicacid. There are many ways to convert biomass into a alkali metal salt ofa carboxylic acid.

Continuing with the example where the biomass is a lipid and theintermediate conversion step of saponification has been used (seeparagraph 7 above), the next step is to separate the R—COONa andincorporate this chemical into an anolyte for use in an electrolyticcell. This anolyte may also include a solvent (such as methanol) andoptionally a supporting electrolyte (in addition to the R—COONa) such assodium acetate.

The anolyte is fed into an electrolytic cell that uses a sodium ionconductive ceramic membrane that divides the cell into two compartments:an anolyte compartment and a catholyte compartment. A typical membraneis a NaSICON membrane. NaSICON typically has a relatively high ionicconductivity for sodium ions at room temperature. Alternatively, if thealkali metal is lithium, then a particularly well suited material thatmay be used to construct an embodiment of the membrane is LiSICON.Alternatively, if the alkali metal is potassium, then a particularlywell suited material that may be used to construct an embodiment of themembrane is KSICON. Other examples of such solid electrolyte membranesinclude those based on NaSICON structure, sodium conducting glasses,beta alumina and solid polymeric sodium ion conductors. Such materialsare commercially available. Moreover, such membranes are tolerant ofimpurities that may be in the anolyte and will not allow the impuritiesto mix with the catholyte. Thus, the impurities (which were derived fromthe biomass) do not necessarily have to be removed prior to placing theanolyte in the cell.

The electrolytic cell may use standard parallel plate electrodes, whereflat plate electrodes and/or flat membranes are used. In otherembodiments, the electrolytic cell may be a tubular type cell, wheretubular electrodes and/or tubular membranes are used.

An electrochemically active first anode may be found in the cell and maybe housed in the first anolyte compartment. The anode may be made ofsmooth platinum, stainless steel, or may be a carbon based electrode.Examples of carbon based electrodes include boron doped diamond, glassycarbon, synthetic carbon, Dimensionally Stable Anodes (DSA), and leaddioxide. Other materials may also be used for the electrode. The firstanode allows the desired reaction to take place. In this anolytecompartment of the cell, the oxidation (decarboxylation) reaction andsubsequent radical-radical coupling takes place. In one embodiment, theanodic decarboxylation/oxidative coupling of carboxylic acids occurs viaa reaction known as the “Kolbe reaction.” The standard Kolbe reaction isa free radical reaction and is shown below:

This Kolbe reaction is typically conducted in non-aqueous methanolicsolutions, with partially neutralized acid (in the form of alkali salt)used with a parallel plate type electrochemical cell. The anolyte usedin the cell may have a high density.

As can be seen from the Kolbe reaction, the “R” groups of two carboxylicacid molecules are coupled together, thereby resulting in a coupledradical product. In one embodiment, the Kolbe reaction is a free radicalreaction in which two “R radicals” (R.) are formed and are subsequentlycombined together to form a carbon-carbon bond. It will be appreciatedby those of skill in the art, that depending upon the starting materialused, the coupled radical product may be a hydrocarbon or some othercarboxylic acid chain. The coupled radical product may be a dimer, or amixed product comprising one or more high- or low-carboxylic acids. Theradical in the coupled radical product may include an alkyl-basedradical, a hydrogen-based radical, an oxygen-based radical, anitrogen-based radical, other hydrocarbon radicals, and combinationsthereof. Thus, although hydrocarbons may be used in the examples belowas the coupled radical product, hydrocarbon may be freely substitutedfor some other appropriate coupled radical product.

As noted above, however, the present embodiments may use a sodium salt(or alkali metal salt) of the carboxylic acid in the anolyte rather thanthe carboxylic acid itself. Thus, rather than using the standard Kolbereaction (which uses a carboxylic acid in the form of a fatty acid), thepresent embodiments may involve conducting the following reaction at theanode:

Again, this embodiment results in two “R” groups being coupled togetherto form a coupled radical product such as a hydrocarbon. There aredistinct advantages of using the sodium salt of the carboxylic acidinstead of the carboxylic acid itself:

-   -   R—COONa is more polar than R—COOH and so it is more likely to        decarboxylate (react) at lower voltages;    -   The electrolyte conductivity may be higher for sodium salts of        carboxylic acids than carboxylic acids themselves; and    -   The anolyte and catholyte may be completely different allowing        different reactions to take place at either electrode.

As noted above, the cell contains a membrane that comprises a sodium ionconductive membrane. This membrane selectively transfers sodium ions(Na⁺) from the anolyte compartment to the first catholyte compartmentunder the influence of an electrical potential, while at the same timepreventing the anolyte and catholyte from mixing.

The catholyte may be aqueous NaOH or a non aqueous methanol/sodiummethoxide solution. (The anolyte may also be aqueous or non-aqueous). Anelectrochemically active cathode is housed in the catholyte compartment,where reduction reactions take place. These reduction reactions may bewritten as:

2Na⁺+2H₂O+2e ⁻→2NaOH+H₂

2Na⁺+2CH₃OH+2e ⁻→2NaOCH₃+H₂

Hydrogen gas is the product of the reduction reaction at the cathode.NaOH (sodium hydroxide) or NaOCH₃ (sodium methoxide) is also produced.This NaOH or NaOCH₃ is the base that was used above in thesaponification reaction. Thus, this reaction may actually regenerate (inthe catholyte compartment) one of the reactants needed in the overallprocess. This NaOH or NaOCH₃ may be recovered and re-used in furtherreactions. The ability to regenerate and re-use the NaOH or NaOCH₃ isadvantageous and may significantly reduce the overall costs of theprocess.

In an alternative embodiment, a sodium salt of carboxylic acid with asmall number of carbon atoms (such as CH₃COONa (sodium acetate)) may beadded to the anolyte in addition to the R—COONa. The addition of sodiumacetate may be advantageous in some embodiments because:

-   -   Sodium acetate may act as a suitable supporting electrolyte as        it is highly soluble in methanol solvent (up to 26 wt. %),        thereby providing high electrolyte conductivity in the anolyte;    -   Sodium acetate will itself decarboxylate (in the electrolytic        process) and produce CH₃. (methyl radicals) by the following        reaction:

-   -   In turn, the methyl radical may react with a hydrocarbon group        of the carboxylic acid to form hydrocarbons with additional CH₃—        functional group:

Therefore, in one embodiment, by using sodium acetate as part of theanolyte, this embodiment may couple two hydrocarbon radicals from thecarboxylic acid together (R—R) or couple the radical of the carboxylicacid with a methyl radical from the acetate (R—CH₃), thereby producingmixed hydrocarbon products. This mixture of products may be separatedand used as desired. Of course, this embodiment is shown using sodiumacetate as the additional reactant. In the alternative, other sodiumsalts of a carboxylic acid with a small number of carbon atoms may alsobe used to couple a carbon radical to the radical of the carboxylicacid.

It will be appreciated that a variety of different hydrocarbons orcoupled radical products may be formed using the present embodiments.For example, the particular “R” group that is selected may be chosenand/or tailored to produce a hydrocarbon that may be used for diesel,gasoline, waxes, JP8 (“jet propellant 8”), etc. The particularapplication of the hydrocarbon may depend upon the starting materialchosen.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In order that the manner in which the above-recited and other featuresand advantages of the invention are obtained will be readily understood,a more particular description of the invention briefly described abovewill be rendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 is a schematic diagram illustrating various embodiments ofprocesses that may be used to produce a coupled radical product in theform of hydrocarbon from biomass;

FIG. 2 is a schematic view of an electrolytic cell for conversion ofsodium salts of fatty acids to coupled radical products by anodicdecarboxylation and subsequent carbon-carbon bond formation inaccordance with the present embodiments;

FIG. 3 is a schematic view of another embodiment of an electrolytic cellfor conversion of sodium salts of fatty acids to coupled radicalproducts;

FIG. 4 is a schematic view of another embodiment of an electrolytic cellfor conversion of sodium salts of fatty acids to coupled radicalproducts;

FIG. 5 is a schematic view of another embodiment of an electrolytic cellfor conversion of sodium salts of fatty acids to coupled radicalproducts;

FIG. 6 is a flow diagram showing one embodiment of a process of forminga hydrocarbon;

FIG. 7 is a flow diagram showing another embodiment of a process offorming a hydrocarbon;

FIG. 8 is a graph of voltage versus time during the decarboxylation ofan anolyte according to the present embodiments; and

FIG. 9 is a graph of voltage versus time during the decarboxylation ofan anolyte according to the present embodiments.

DETAILED DESCRIPTION

A method for producing a coupled radical product from biomass isdisclosed. This method comprises obtaining a quantity of biomass andthen converting the biomass into an at least one alkali metal salt of acarboxylic acid. In some embodiments, the alkali metal may comprisesodium such that the alkali metal salt of the carboxylic acid comprisesa sodium salt of the carboxylic acid. An anolyte may comprise a quantityof the alkali metal salt of the carboxylic acid. In one embodiment, thealkali metal salt of the carboxylic acid is decarboxylated. Thedecarboxylation converts the alkali metal salt of the carboxylic acidinto an alkyl radical that reacts to form the coupled radical product.In one embodiment, the coupled radical product is a hydrocarbon. Amixture of hydrocarbons may also be produced. The alkyl radical maycouple to another alkyl radical or to a hydrogen radical. The hydrogenradicals may be formed in addition to the alkyl radicals. The hydrogenradicals may also be formed from an alkali metal formate or from aphotolysis process of hydrogen gas within the anolyte compartment. Itwill be appreciated by those of skill in the art that any irradiationprocess may be used instead of photolysis. The decarboxylation of thealkali metal salt of the carboxylic acid may also be performed viaphotolysis. At least one alkali metal salt of the carboxylic acid mayfurther comprise a quantity of an alkali metal acetate and/or a quantityof an alkali metal formate.

The biomass may be converted into at least one alkali metal salt of acarboxylic acid in a variety of different ways. For example, embodimentsmay be constructed in which converting the biomass comprisessaponification, wherein a base is reacted with a quantity of thecarboxylic acid to produce the alkali metal salt of the carboxylic acid.In other embodiments, a lipid is extracted from the biomass, and, ifnecessary, the lipid may be hydrolyzed to form carboxylic acid. Thiscarboxylic acid may then be saponified to produce at least one alkalimetal salt of carboxylic acid. In other embodiments, the biomass isfermented to produce a carboxylic acid. The carboxylic acid may then besaponified to produce at least one alkali metal salt of carboxylic acid.In other embodiments, the biomass is fermented to directly produce atleast one alkali metal salt of carboxylic acid. Further embodiments aredesigned in which a carbohydrate is hydrolyzed to produce a carboxylicacid (which may then be saponified). The saponification may occur in thesame electrolytic cell where decarboxylation occurs. In otherembodiments, a base is reacted directly with a quantity of biomass toproduce the at least one alkali metal salt of the carboxylic acid.Accordingly, the alkali metal salt may be derived from carbohydrates,lipids, such as oils, including tall oil, fatty acids, esters of fattyacids, triglycerides of fatty acids, phospholipids, fatty acidderivatives, and/or metal salts of fatty acids, lignins, such as resins,and mixtures of the foregoing. The alkali metal salt of the carboxylicacid may be derived from the forgoing in the form of wood chips,forestry residue, energy crops (switch grass, miscanthus, sorghum,energy cane and other genetically modified plants), algae,cyanobacteria, jatropha, soy bean, corn, palm, coconut, canola,rapeseed, Chinese tallow, animal fats and products of geneticallymodified organisms, whether natural, synthetic, man-made, or evengenetically altered.

The electrolytic cell used to decarboxylate alkali metal salt of thecarboxylic acid may comprise an anolyte compartment and a catholytecompartment. The anolyte compartment houses the anolyte and thecatholyte compartment houses a catholyte. The anolyte compartment andthe catholyte compartment are separated by an alkali ion conductingmembrane. In some embodiments, the alkali ion conducting membrane is aNaSICON membrane. During this reaction, the catholyte in the catholytecompartment produces hydrogen gas and a base. This base may or may notbe the same base used in the saponification reaction that produces thealkali metal salt of the carboxylic acid. The anolyte and catholyte mayboth comprise a solvent. The anolyte may comprise a first solvent or afirst mixture of solvents, and the catholyte may comprise a secondsolvent or second mixture of solvents, wherein the first solvent or thefirst mixture of solvents included in the anolyte do not have to be thesame as the second solvent or the second mixture of solvents included inthe catholyte. The first solvent may comprise a two-phase solventsystem, wherein one phase is capable of dissolving ionic materials andthe other phase is capable of dissolving non-ionic materials. Theanolyte may be reacted at a higher temperature and/or pressure than thecatholyte (or vice versa).

A method for producing a coupled radical product is also disclosed. Themethod comprises preparing an anolyte for use in an electrolytic cell,the cell comprising an alkali ion conducting membrane, wherein theanolyte comprises a first solvent and a quantity of an alkali metal saltof a carboxylic acid. The method also comprises decarboxylating at leastone alkali metal salt of the carboxylic acid within the cell, whereinthe decarboxylation converts at least one alkali metal salt of thecarboxylic acid into an alkyl radical that reacts to form a coupledradical product. In one embodiment, the coupled radical product is ahydrocarbon.

Another method of producing a coupled radical product is also disclosed.The method may comprise obtaining a alkali metal salt of a carboxylicacid, the alkali metal salt being derived from, for example,carbohydrates, fatty acids, dicarboxylic fatty acids, polycarboxylicfatty acids, esters of fatty acids, triglycerides of fatty acids,lipids, phospholipids, fatty acid derivatives, and/or metal salts ofcarboxylic acids. The method may also comprise preparing an anolyte foruse in an electrolytic cell, the electrolytic cell comprising an anolytecompartment, a catholyte compartment, and a NaSICON membrane thatseparates the anolyte compartment from the catholyte compartment,wherein anolyte is housed within the anolyte compartment and catholyteis housed within the catholyte compartment. The anolyte comprises asolvent and a quantity of the sodium salt of the carboxylic acid. Theanolyte is electrolyzed within the cell, wherein the electrolyzingdecarboxylates the sodium salt of the carboxylic acid and converts thesodium salt of the carboxylic acid into an alkyl radical that reacts toform a coupled radical product, which in one embodiment, may be ahydrocarbon.

The embodiments of the present invention will be best understood byreference to the drawings, wherein like parts are designated by likenumerals throughout. It will be readily understood that the componentsof the present invention, as generally described and illustrated in thefigures herein, could be arranged and designed in a wide variety ofdifferent configurations. Thus, the following more detailed descriptionof the present embodiments, as represented in the Figures, is notintended to limit the scope of the invention, as claimed, but is merelyrepresentative of embodiments of the invention.

FIG. 1 is a schematic diagram of an embodiment of the method (process)100 described herein. Specifically, this process involves obtaining aquantity of biomass 104. The biomass 104 may comprise, for example,carbohydrates, lipids, such as oils, including tall oil, and lignins,such as resins. The biomass may also include lipids such as fatty acids,esters of fatty acids, triglycerides of fatty acids, phospholipids,fatty acid derivatives, and/or metal salts of fatty acids. Otherexamples of biomass include wood chips, forestry residue, energy crops(switch grass, miscanthus, sorghum, energy cane and other geneticallymodified plants), algae, cyanobacteria, jatropha, soy bean, corn, palm,coconut, canola, rapeseed, Chinese tallow, animal fats and products ofgenetically modified organisms. The biomass may be a variable or impurefeedstock. As indicated above, the biomass 104 may be from algal,animal, microbial, or plant origins (such as wood, switch grass, etc.).In one embodiment, any type of biomass may be used, whether the sourceof this biomass 104 is natural, synthetic, man-made, or even geneticallyaltered (such as in the case of microbes, microorganisms, or animals).If the biomass is from an algal material, the algae may be synthesized,genetically-altered, or may be naturally occurring. Mixtures ofdifferent types of biomass may also be used. As explained in detailherein, the biomass 104 may be used as a starting material to ultimatelyarrive at an alkali metal salt of a carboxylic acid 108 (which may bereferred to as an “alkali metal salt of a fatty acid” 108 as used in thedescription below).

As shown in FIG. 1, there are a variety of different methods, processes,and/or chemical reactions that will convert the biomass 104 into thealkali salt of the fatty acid. In some embodiments, the produced alkalimetal salt of the carboxylic acid comprises a sodium salt. Other alkalimetal salts, such as lithium salts or potassium salts, may also be used.For example, in one embodiment, the biomass 104 will be converted via anextraction process 111 into a lipid material 112. This lipid material112 may be a synthetic or naturally occurring lipid, microbiallyproduced (either biochemically or chemically), branched or unbranched,saturated or unsaturated, or any other type of lipid material. Examplesof this lipid material 112 include phospholipids, steroids, oils, waxes,fatty acids, esters of fatty acids, triglycerides of fatty acids, fattyacid derivatives, and/or metal salts of fatty acids. Dicarboxylic acids,tricarboxylic acids, olego carboxylic acids, or polycarboxylic acids mayalso be used as the lipid.

This lipid material 112 may be subjected to a hydrolysis process 115that converts the lipid 112 into a fatty acid 120 (such as carboxylicacid 120). In turn, this fatty acid 120 may undergo a saponificationreaction 121 to produce the alkali salt of the fatty acid 108. As shownin FIG. 1, the saponification reaction may involve reacting the fattyacid 120 with a base 150. Examples of the base 150 include sodiumhydroxide, sodium methoxide, sodium methylate, sodium ethoxide oranother caustic agent. Other embodiments may be designed in which thereaction is accomplished via another sodium containing compound (oralkali metal containing compound) or even metallic sodium or anothermetallic alkali metal. Additionally or alternatively, the lipid 112 maybe subjected to a conversion reaction 123 (such as an alkali metalhydrolysis and/or a saponification process) which converts the lipid 112into at least one alkali metal salt of the fatty acid 108.

The saponification reaction uses the base 150 to produce an alkali metalsalt of a fatty acid. Examples of this reaction are shown below usingsodium methoxide or NaOH as the base:

R—COOX+CH₃ONa→R—COONa+CH₃OH

R—COOX+NaOH→R—COONa+H₂O

The “R” in this embodiment represents the hydrocarbon tail orhydrocarbon moiety of the molecule. The “X” represents the remainingsection of an ester, the remaining section of a triglyceride, a hydrogenor a metal other than sodium. As shown by this reaction, R—COONa isproduced, which is the sodium salt of the fatty acid.

As shown in FIG. 1, in other embodiments, the biomass 104 may undergo afermentation reaction 131 that converts the biomass 104 into a fattyacid 120. In some embodiments, this fatty acid may be acetic acid 134.The acetic acid 134 and/or the fatty acid 120 may then undergo thesaponification reaction 121 to produce the alkali salt of the fatty acid108. If acetic acid 134 is obtained, the saponification reaction willproduce a quantity of an alkali acetate 158. Optionally, the alkali saltof the fatty acid 108 may be mixed with an alkali acetate 158. Theacetate 158 may be obtained from any suitable source, including thebiomass itself. Other types of conversion reactions 123 may also beused. Other embodiments may be designed in which algae, or algaeproducts, are converted directly to an alkali metal salt of the fattyacid.

In other embodiments, the fermentation reaction 131 may convert thebiomass 104 into a lipid material 112, as shown by dashed line 131 a.This is especially useful for biomass from tall oils, pulp produced frompaper mills, etc. Such lipid materials 112 may then be processed in themanner outlined above.

In other embodiments, the biomass 104 may be a carbohydrate 140. Thiscarbohydrate material 140 may undergo a hydrolysis reaction 143 thatconverts the carbohydrate into acetic acid 134 and/or into another fattyacid 120. The particular carbohydrate material used will determinewhether the resulting acid is branched or unbranched, saturated orunsaturated. Examples of carbohydrates could be starch, cellulose,hemi-cellulose, glucose, pentoses, and sucrose. Once the acetic acid 134or fatty acid 120 has been obtained, this acid may be subjected tosaponification 121 to produce the alkali salt of the fatty acid 108.Other types of conversion reactions that convert the carbohydrate intothe alkali salt of the fatty acid 108 may also be used.

In other embodiments, the biomass 104 comprises tall oil, resins, and/orlignins 190. Such materials may be converted 192 into carboxylic acids120 (and then processed as outlined herein). In one embodiment, thelignin 190 is first subjected to a conversion reaction 192 whereby thelignin is hydrolyzed into carboxylic acid and then saponified into thealkali metal salt of carboxylic acid. In other embodiments, thematerials 190 may be directly converted 191 to the alkali metal salts ofcarboxylic acids.

It should be noted that the various processes described and shown inFIG. 1 are not limiting. In certain embodiments, any type of biomass maybe used. Also, other processes may be employed within the disclosedmethods.

Once the alkali salt of the fatty acid 108 has been obtained, the saltof the fatty acid 108 will be added to an electrochemical cell thatincludes a sodium conducting membrane (or other alkali conductingmembrane). An example of a typical embodiment of a cell is shown in FIG.2. This cell, which may also include a quantity of a first solvent 160(which may be, for example, an alcohol like methanol, ethanol, and/orglycerol), may use an advanced Kolbe reaction 167. The solvent 160 maybe obtained from the base 150, or may be obtained from any other source.This advanced Kolbe reaction produces a hydrocarbon 170 along with aquantity of carbon dioxide 172 and a base 174. As discussed above, incertain embodiments, the hydrocarbon 170 is but one example of any of anumber of coupled radical products that may be produced by this process.The base 174 may be the same as the base 150 that was used in thesaponification reaction 121. By forming the base as part of thereaction, the base used in saponification may be regenerated andrecycled over the entire process. The regeneration of the base 150obviates the need to purchase new quantities of base in order to repeatthe process. Likewise, because the base is re-used, disposal costsassociated with disposing of the base may be avoided. Similarly, thecarbon dioxide 172 produced in the process 100 is a safe,naturally-occurring chemical and may be disposed of, collected, sold,etc.

The hydrocarbon 170 produced in the process 100 (and more specificallyin the advanced Kolbe reaction 167) may be of significant value.Hydrocarbons have significant value for use in fuels, diesel fuels,gasoline, medical applications, waxes, perfumes, oils, and otherapplications and products. With the process of the present invention,different types of hydrocarbons may be used. Hydrocarbons are oftenclassified by the number of carbons in their chain. In addition,hydrocarbons may often be classified into the following “fractions”:

C₁ Methane fraction C₂-C₅ Natural gas fraction C₆-C₁₀ Gasoline fractionC₁₀-C₁₃ JP8 fraction C₁₄-C₂₀ Diesel fraction C₂₀-C₂₅ Fuel Oil fractionC₂₀-C₃₀ WaxesNote that these classifications are not exact and may change accordingto the particular embodiment. For example, the “gasoline fraction” couldhave a portion of C₁₁, the JP8 fraction could have some C₁₄, etc.

By forming the coupled radical products according to the presentembodiments, various hydrocarbons could be made in some or all of thesefractions. For example, embodiments may be constructed in which a C₈hydrocarbon (octane) is formed, which is a principal ingredient incommercial gasoline. Likewise, a C₁₂ hydrocarbon may be formed, whichmay be used in making JP8. Of course, the exact product that is obtaineddepends upon the particular starting material(s) and/or the reactionconditions used. Thus, the present embodiments allow biomass to beconverted into synthetic lubricants, gasoline, JP8, diesel fuels, orother hydrocarbons.

In order to form the hydrocarbon, an advanced Kolbe reaction 167 occurswithin an electrochemical cell. This reaction, along with an example ofa typical cell, will now be described in greater detail in conjunctionwith FIG. 2. Specifically, FIG. 2 shows a cell 200 (which may be anelectrochemical cell to which a voltage may be applied). The cell 200includes a catholyte compartment 204 and an anolyte compartment 208. Thecatholyte compartment 204 and the anolyte compartment 208 may beseparated by a membrane 212.

The particulars of each cell 200 will depend upon the specificembodiment. For example, the cell 200 may be a standard parallel platecell, where flat plate electrodes and/or flat plate membranes are used.In other embodiments, the cell 200 may be a tubular type cell, wheretubular electrodes and/or tubular membranes are used. Anelectrochemically active first anode 218 is housed, at least partiallyor wholly, within the anolyte compartment 208. More than one anode 218may also be used. The anode 218 may comprise, for example, a smoothplatinum electrode, a stainless steel electrode, or a carbon basedelectrode. Examples of a typical carbon based electrode include borondoped diamond, glassy carbon, synthetic carbon, Dimensionally StableAnodes (DSA) and relatives, and/or lead dioxide. Other electrodes maycomprise metals and/or alloys of metals, including S.S, Kovar,Inconel/monel. Other electrodes may comprise RuO₂—TiO₂/Ti,PtO_(x)—PtO₂/Ti, IrO_(x), CO₃O₄, MnO₂, Ta₂O₅ and other valve metaloxides. In addition, other materials may be used to construct theelectrode such as SnO₂, Bi₂Ru₂O₇ (BRO), BiSn₂O₇, noble metals such asplatinum, titanium, palladium, and platinum clad titanium, carbonmaterials such as glassy carbon, BDD, or Hard carbons. Additionalembodiments may have RuO₂—TiO₂, hard vitrems carbon, and/or PbO₂. Again,the foregoing serve only as examples of the type of electrodes that maybe employed. The cathode compartment 204 includes at least one cathode214. The cathode 214 is partially or wholly housed within the cathodecompartment 204. The material used to construct the cathode 214 may bethe same as the material used to construct the anode 218. Otherembodiments may be designed in which a different material is used toconstruct the anode 218 and the cathode 214.

The anolyte compartment 208 is designed to house a quantity of anolyte228. The catholyte compartment 204 is designed to house a quantity ofcatholyte 224. In the embodiment of FIG. 2, the anolyte 228 and thecatholyte 224 are both liquids, although solid particles and/or gaseousparticles may also be included in either the anolyte 228, the catholyte224, and/or both the anolyte 228 and the catholyte 224.

The anode compartment 208 and the cathode compartment 204 are separatedby an alkali metal ion conductive membrane 212. The membrane utilizes aselective alkali metal transport membrane. For example, in the case ofsodium, the membrane is a sodium ion conductive membrane 212. The sodiumion conductive solid electrolyte membrane 212 selectively transferssodium ions (Na⁺) from the anolyte compartment 208 to the catholytecompartment 204 under the influence of an electrical potential, whilepreventing the anolyte 228 and the catholyte 224 from mixing. Examplesof such solid electrolyte membranes include those based on NaSICONstructure, sodium conducting glasses, beta alumina and solid polymericsodium ion conductors. NaSICON typically has a relatively high ionicconductivity at room temperature. Alternatively, if the alkali metal islithium, then a particularly well suited material that may be used toconstruct an embodiment of the membrane is LiSICON. Alternatively, ifthe alkali metal is potassium, then a particularly well suited materialthat may be used to construct an embodiment of the membrane is KSICON.

As noted above, the saponification reaction 121 and/or the otherreactions of FIG. 1 are designed to produce a quantity of an alkalimetal salt of a fatty acid 108. This alkali metal salt of a fatty acid108 may be separated and/or purified, as needed. Likewise, as desired,if the alkali metal salt of a fatty acid 108 comprises a mixture offatty acid salts, these compounds may be separated. Alternatively, thealkali metal salt of a fatty acid 108 may not be separated and maycomprise a mixture of different fatty acid salts. As explained above,the alkali metal salt of a fatty acid 108 may have a structureR—COO—AlMet, wherein “R” represents the fatty acid moiety, and “AlMet”represents the alkali metal ion. For example, if the alkali metal issodium, then the alkali metal salt of a fatty acid 108 will generallyhave the structure R—COONa.

The anolyte compartment 208 may include one or more inlets 240 throughwhich the anolyte 228 may be added. Alternatively, the components thatmake up the anolyte 228 may be separately added to the anolytecompartment 208 via the inlets 240 and allowed to mix in the cell. Theanolyte includes a quantity of the alkali metal salt of a fatty acid108. In the specific embodiment shown in FIG. 2, sodium is the alkalimetal, so that alkali metal fatty acid salt 108 is a sodium salt 108 a.The anolyte 228 also includes a first solvent 160, which as noted above,may be an alcohol 160 a. Of course, other types of solvents may also beused. The anolyte 228 may optionally include the alkali metal acetate158, such as sodium acetate 158 a.

The catholyte compartment 204 may include one or more inlets 242 throughwhich the catholyte 224 may be added. The catholyte 224 includes asecond solvent 160 b. The second solvent 160 b may be an alcohol orwater (or a mixture of alcohol and water). Significantly, the solvent160 b in the catholyte 224 is not necessarily the same as the firstsolvent 160 a in the anolyte 228. In some embodiments, the solvents 160a, 160 b may be the same. The reason for this is that the membrane 212isolates the compartments 208, 204 from each other. Thus, the solvents160 a, 160 b may be each separately selected for the reactions in eachparticular compartment (and/or to adjust the solubility of the chemicalsin each particular compartment). Thus, the designer of the cell 200 maytailor the solvents 160 a, 160 b for the reaction occurring in thespecific compartment, without having to worry about the solvents mixingand/or the reactions occurring in the other compartment. This may be asignificant advantage in designing the cell 200. A typical Kolbereaction only allows for one solvent used in both the anolyte and thecatholyte. Accordingly, the use of two separate solvents may beadvantageous. In other embodiments, either the first solvent 160 a, thesecond solvent 160 b, and/or the first and second solvents 160 a, 160 bmay comprise a mixture of solvents.

The catholyte 224 may also include a base 150. In the embodiment of FIG.1, the base 150 may be NaOH or sodium methoxide, or a mixture of thesechemicals. The base 150 may be the same base 150 as used in thesaponification reaction 121 of FIG. 1. Alternatively, the base may be adifferent base than that which was used in the saponification reaction(as shown by reference number 150 a).

The reactions that occur at the anode 218 and cathode 214 will now bedescribed. As with all electrochemical cells, such reactions may occurwhen voltage source 290 applies a voltage to the cell 200.

At the cathode 214, a reduction reaction takes place. This reaction usesthe sodium ions and the solvent to form hydrogen gas 270 as well as anadditional quantity of base 150/150 a. Using the chemicals of FIG. 2 asan example, the reduction reaction may be written as follows:

2Na⁺+2H₂O+2e ⁻→2NaOH+H₂

2Na⁺+2CH₃OH+2e ⁻→2NaOCH₃+H₂

The hydrogen gas 270 and/or the base 150/150 a may be extracted throughoutlets 244. The hydrogen gas 270 may be gathered for further processingfor use in other reactions, and/or disposed of or sold. The productionof the base 150/150 a may be a significant advantage because the base150 that was consumed in the saponification reaction 121 of FIG. 1 isgenerated in this portion of the cell 200. Thus, the base formed in thecell may be collected and re-used in future saponification reactions (orother chemical processes). As the base may be re-used, the hassle and/orthe fees associated with disposing of the base are avoided.

The reactions that occur at the anode 218 may involve decarboxylation.These reactions may involve an advanced Kolbe reaction (which is a freeradical reaction) to form a quantity of a hydrocarbon 170 and carbondioxide 172. Using the chemicals of FIG. 2 as an example, the oxidationreactions may be written as follows:

The carbon dioxide 172 may be vented off (via outlets 248). This is asafe, naturally-occurring chemical that may be collected, disposed of,or re-used. The coupled radical product 170 may also be collected via anoutlet 248. For example, a quantity of the solvent 160/160 a may beextracted via an outlet 248 and recycled, if desired, back to the inlet240 for future use.

The advanced Kolbe reaction may comprise a free radical reaction. Assuch, the reaction produces (as an intermediate) a hydrocarbon radicaldesignated as R.. Accordingly, when two of these R. radicals are formed,these radicals may react together to form a carbon-carbon bond:

As shown in FIG. 2, this R—R hydrocarbon product is designated ashydrocarbon 170 a. In essence, the R moiety is being decarboxylated, asthe carbonyl moeity is removed, leaving only the R. radical that iscapable of reacting to form a hydrocarbon.

As shown in FIG. 2, sodium acetate 158 a (or some other sodium salt ofcarboxylic acid with a small number of carbon atoms) may be part of (oradded to) the anolyte 228. Sodium acetate may act as a suitablesupporting electrolyte as it is highly soluble in methanol solvent (upto 26 wt. %) providing high electrolyte conductivity. At the same time,sodium acetate may itself decarboxylate as part of the advanced Kolbereaction and produce CH₃. (methyl) radicals by the following reaction:

The methyl radicals may then be reacted with hydrocarbon group of thefatty acid to form hydrocarbons with additional CH₃— functional group:

CH₃.+R.→CH₃—R

Alternatively or additionally, the methyl radical may react with anothermethyl radical to form ethane:

CH₃.+CH₃.→CH₃—CH₃

Ethane (CH₃—CH₃) is a hydrocarbon that may form a portion of thehydrocarbon product 170. This ethane is designated as 170 c. The CH₃—Rformed in the reaction may also be part of the hydrocarbon product 170and is designated as 170 b. Thus, a mixture of hydrocarbons may beobtained. If desired, the various hydrocarbons 170 a, 170 b, 170 c maybe separated from each other and/or purified, such as via gaschromatography or other known methods. The present embodiments maycouple two hydrocarbon radicals or couple methyl radicals withhydrocarbon radicals. The amount of the CH₃—R or R—R in the product maydepend upon the particular reaction conditions, quantities of reactantsused in the anolyte, etc.

The foregoing example involved the use of sodium acetate in addition tothe fatty acid salt to produce reactive methyl radicals, therebyproducing CH₃—R in addition to the R—R product. However, rather thanacetate, other salts that have a small number of carbons may be used inplace of or in addition to acetate. These salts having a small number ofcarbons may produce, for example, ethyl radicals, propyl radicals,isopropyl radicals, and butyl radicals during decarboxylation. Thus, bychanging the optional component, additional hydrocarbons may be formedin the cell 200. The user may thus tailor the specific product formed byusing a different reactant. Thus, it is possible to create a mixture ofproducts as different alkyl radicals react together or even react with amethyl radical, a hydrogen radical, etc. The different alkyl radicalsmay be added by adding acetate, formate, etc. into the anolyte through,for example, an additional port in the anolyte compartment. Such adifferent mixture of products may be, in some embodiments, similar towhat would occur in a disproportionation reaction.

In a similar manner, instead of and/or in addition to using sodiumacetate, an alkali metal formate (such as sodium formate) may be used aspart of the anolyte. Sodium formate has the formula H—COONa. During theelectrochemical reaction, the formate, like the acetate, will undergodecarboxylation to form a hydrogen radical:

In turn, this hydrogen radical will react to form:

H.+R.→H—R

AND/OR

H.+H.→H₂

The use of sodium formate as an optional reactant may result in the R—Rproduct being formed as well as a quantity of an R—H product (and even aquantity of hydrogen gas (H₂)). (The hydrogen gas may be re-used ifdesired). The use of formate may prevent the unnecessary formation ofethane and/or may be used to tailor the specific hydrocarbon (R—H)product.

The particular R group that is shown in these reactions may be any “R”obtained from biomass, whether the R includes saturated, unsaturated,branched, or unbranched chains. When the R—R product is formed, this isessentially a “dimer” of the R group. For example, if the R group is CH₃(such as is the case with sodium acetate), two methyl radicals react(2CH₃.) and “dimerize” into ethane (CH₃—CH₃). If the R group is a C₁₈H₃₄hydrocarbon, then a C₃₆H₇₈ product may be formed. By using these simpleprinciples, as well as using the formate or the small chain carbon salt,any desired hydrocarbon may be obtained. For example, by using a C₄sodium salt, a C₈ R—R hydrocarbon may be formed, which may be useable aspart of a gasoline. Likewise, if a C₆ sodium salt is used, a C₁₂ R—Rhydrocarbon may be formed, which may be useable as JP8. Syntheticlubricants, waxes, and/or other hydrocarbons may be formed in the sameor a similar manner.

An alternate embodiment to that of FIG. 2 will now be described withreference to the embodiment shown in FIG. 3. Because much of theembodiment of FIG. 3 is similar to that which is shown in FIG. 2, adiscussion of portions of the similar features will be omitted forpurposes of brevity, but is incorporated herein by this reference.Because the anolyte compartment 208 is separate from the catholytecompartment 204, it is possible to create a reaction environment in theanolyte compartment 208 that is different from the catholyte compartment204. FIG. 3 illustrates this concept. For example, hydrogen gas (H₂) 320may be introduced into the anolyte compartment 208. In some embodiments,the anolyte compartment 208 may be pressurized by hydrogen gas 320. Insome embodiments, the anode 208 or anolyte could include a component 310made of Pd or other noble metal (such as Rh, Ni, Pt, Ir, or Ru) oranother substrate such as Si, a zeolite, etc. (This component may be allor part of the electrode and may be used to immobilize the hydrogen gason the electrode.) Alternatively, Pd or Carbon with Pd could besuspended within the cell. The effect of having hydrogen gas in theanolyte compartment 208 is that the hydrogen gas may form hydrogenradicals (H.) during the reaction process that react in the manner notedabove. These radicals would react with the R. radicals so that theresulting products would be R—H and R—R. If sufficient hydrogen radicals(H.) are present, the R—H product may be predominant, or may be the(nearly) exclusive product. This reaction could be summarized as follows(using Pd as an example of a noble metal, noting that any other noblemetal could be used):

R—COONa+H₂ and Pd→Pd—H_(x)→Pd+H—R+CO₂ +e ⁻+Na⁺

By using one or more of the noble metals with hydrogen gas in theanolyte compartment, the particular product (R—H) may be selected. Inthe embodiment of FIG. 3, hydrogen gas 270 is produced in the catholytecompartment 204 as part of the reduction reaction. This hydrogen gas 270may be collected and used as the hydrogen gas 320 that is reacted withthe noble metal in the anolyte compartment 208. Thus, the cell 300actually may produce its own hydrogen gas 270 supply that will be usedin the reaction. Alternatively, the hydrogen gas 270 that is collectedmay be used for further processing of the hydrocarbon, such as crackingand/or isomerizing waxes and/or diesel fuel. Other processing usinghydrogen gas may also be used. The R—H product helps to minimize theformation of the R—R group (which, if the R group is sufficiently,large, may be a hydrocarbon such as a wax).

Referring now to FIG. 4, an additional embodiment of a cell 400 isillustrated. The cell 400 is similar to the cells that have beenpreviously described. Accordingly, for purposes of brevity, much of thisdiscussion will not be repeated. In the embodiment of FIG. 4, the cell400 is designed such that one or more photolysis reactions may occur inthe anolyte compartment 208. Specifically, a photolysis device 410 isdesigned such that it may emit (irradiate) radiation 412 into theanolyte compartment 208. This irradiation may produce hydrogen radicals(H.). The hydrogen gas 320 may be supplied to the anolyte compartment208 using any of the mechanisms described above, as illustrated by thefollowing equation:

This photolysis process may be combined with the electrolysis process ofthe cell described above:

The hydrogen radicals and the hydrocarbon radicals may then combine toform a mixture of products:

2H.+2R→H—R+R—R+H₂

Alternatively, the photolysis device may be used to conductdecarboxylation and to generate hydrocarbon radicals:

Thus, a combination of photolysis and electrolysis may be used to formthe hydrocarbon radicals and/or hydrogen radicals in the anolytecompartment 208:

This combination of electrolysis and photolysis may speed up the rate ofthe decarboxylation reaction.

Yet additional embodiments may be designed using such photolysistechniques. For example, the following reactions may occur:

This combination of reactions (using photolysis and electrolysis) formscarbocations and H⁻ anions that may combine to form the hydrocarbon.Thus, photolysis may be used as a further mechanism for forminghydrocarbons. As has been discussed above, although hydrocarbons arebeing used in these examples, the coupled radical product need not be ahydrocarbon. In certain embodiments, the method and apparatus of thepresent invention may be used to create nonhydrocarbon radicals whichmay couple together to form useful coupled radical products.

Referring now to FIGS. 2-4 collectively, it is noted that each of theseillustrative embodiments involve separation of the anolyte compartment208 and the catholyte compartment 204 using the membrane 212. Asdescribed herein, specific advantages may be obtained by having such amembrane 212 to separate the anolyte compartment 208 from the catholytecompartment 204. These advantages include:

-   -   two separate environments for different reaction conditions—for        example, the anolyte may be non-aqueous, while the catholyte is        aqueous (and vice versa);    -   anolyte may be at a higher temperature than the catholyte (and        vice versa);    -   anolyte may be pressurized and catholyte not (and vice versa);    -   anolyte may be irradiated and catholyte not (and vice versa);    -   anolyte and/or anode may be designed to conduct specific        reactions that are not dependent upon the catholyte and/or        cathode reactions (and vice versa);    -   the different chambers may have different flow conditions,        solvents, solubilities, product retrieval/separation mechanisms,        polarities, etc.        The ability to have separate reaction conditions in the anolyte        compartment and catholyte compartment may allow the reactions in        each compartment to be tailored to achieve optimal results.

Likewise, a membrane, comprising, for example, NaSICON, has a hightemperature tolerance and thus the anolyte may be heated to a highertemperature without substantially affecting the temperature of thecatholyte (or vice versa). (NaSICON can be heated and still functioneffectively at higher temperatures). This means that polar solvents (ornon-polar solvents) that dissolve fatty acids and sodium salts at hightemperatures may be used in the anolyte. For example, palmitic acid maybe heated to form a liquid and this liquid is an excellent solvent forsodium palmitate. At the same time, the catholyte is unaffected bytemperature. In fact, a different solvent system could simultaneously beused in the catholyte. Alternatively, other molten salts or acids may beused to dissolve ionic sodium carboxylic acids and salts in the anolyte.Long chain hydrocarbons, ethers, triglycerides, esters, alcohols, orother solvents may dissolve carboxylic acids and sodium salts. Suchcompounds could be used as the anolyte solvent without affecting thecatholyte. Ionic liquids could be used as the anolyte solvent. Thesematerials not only would dissolve large quantities of fatty acid sodiumsalts, but also, may operate to facilitate the decarboxylation reactionat higher temperatures. Ionic liquids are a class of chemicals with verylow vapor pressure and excellent dissolving abilities/dissolvingproperties. A variety of different ionic liquids may be used.

Referring now to FIG. 5, another embodiment of a cell 500 is shown. Thiscell 500 is similar to that which is described above in conjunction withthe other Figures. Accordingly, for purposes of brevity, thisdescription will not be repeated, but is incorporated by referenceherein.

As explained above, one of the advantages of the present cell is that itproduces a base 150 in the catholyte compartment 204. As noted above,this base 150 may then be used as part of the saponification reaction121 that produces the sodium salt of the fatty acid. In the context ofFIG. 5, this regeneration of the base 150 occurs via the followingreaction:

2H₂O+2e ⁻+2Na⁺→2NaOH+H₂

2CH₃OH+2e ⁻+2Na⁺→2NaOCH₃+H₂

The Na⁺ ions for this reaction come from the anolyte 228. Specifically,the sodium ions migrate through the membrane 212 as shown by FIG. 5. Thebase 150 produced in such reactions is either NaOH or NaOCH₃ which maybe recycled and used in the saponification reactions.

Alternatively, embodiments may be made in which the fatty acids may besaponified directly in the catholyte compartment 208. In other words,the saponification reaction 121 occurs within the cell itself to producethe fatty acid sodium salt, and this sodium salt is then taken from thecatholyte compartment 204 to the anolyte compartment 208 (such as viaconduit 510). Fatty acid is added to the catholyte 224 and may react(saponified) as follows:

R—COOH+2e ⁻+2Na⁺→R—COONa+H₂

This R—COONa is the sodium salt of the fatty acid 108, which is thenintroduced into the anolyte compartment 208 either through a conduit 510(or perhaps through an inlet 240). This sodium salt would then bereacted (decarboxylated), forming coupled radical products such ashydrocarbons. This process thus allows the fatty acid to be saponifiedin situ (e.g., within the cell). This process would be a one stepprocess (e.g., simply running the cell) rather than a two step process(saponification and decarboxylation within the cell).

Triglycerides may also be saponified as used in the present processes.Such saponification may occur within the cell 500 or exterior of thecell. Such saponification of triglycerides may occur, for example, asfollows:

If sodium methoxide (or another organic base) is used rather than sodiumhydroxide, the reaction with a triglyceride may be as follows:

Referring now to FIGS. 2-5, it is apparent that the present embodimentsallow for a ready separation of the produced hydrocarbon material in theanolyte compartment 208. This may occur by having the anolytecompartment 208 include a mixture of solvents 160. For example, thesolvent may comprise an organic phase solvent (such as a non-ionic,non-aqueous solvent). (Inorganic or other solvents may also be used.) Anexample of such a solvent would be a long chain fatty acid alcohol, orother similar organic solvent. Mixed with this organic phase solvent isan ionic solvent or aqueous solvent, such as water or an ionic liquid.This water/ionic liquid dissolves the sodium salt of the fatty acid.This two-phase solvent system is shown in FIG. 5. Specifically, thefirst solvent 160 a comprises a mixture of a first phase solvent 160 c(such as an aqueous phase) and a second phase solvent 160 d (such as anorganic solvent) Likewise, the second solvent 160 b comprises a mixtureof a first phase solvent 160 e (such as an aqueous phase) and a secondphase solvent 160 f (such as an organic solvent).

Using this type of “two-phase” system, the hydrocarbon, when formed,will readily dissolve in the organic phase, and will be repelled by theaqueous/ionic phase. This means that the formed hydrocarbon(s) willreadily separate from the aqueous/ionic phase. The reaction may besummarized as follows:

Similar separation may be obtained by using two solvents of differentpolarities as well. Another example of this principle involves glutaricacid. Sodium glutarate is not soluble in methanol, but is soluble inwater. Accordingly, if water is used as one of the solvents in atwo-phase system, it will dissolve the sodium glutarate. Anothernon-polar and/or organic solvent is used with water. When thehydrocarbon is formed, this hydrocarbon is not soluble in water. Rather,the hydrocarbon will dissolve into the non-polar/organic solvent. Thereactions associated with this example are provided below:

This hydrocarbon H—(CH₂)₃—CH₂)₃—CH₂)₃—H is non-polar and will migrate tothe non-polar/organic solvent. Also, the non-polar nature of the solventmay also operate to terminate the reaction so that a product with ninecarbon atoms forms, rather than allowing a larger polymer to form (byrepeated addition of the —(CH₂)₃— monomer unit). Thus, by selecting theparticular solvent, the reaction conditions for a di-, tri-, orpolycarboxylic acid may be tailored to produce a specific product. Thisuse of organic or inorganic solvents may also be applied to thecatholyte in a similar manner.

In one embodiment, the anolyte comprises G-type solvents, H-Typesolvents, and/or mixtures thereof. G-type solvents are di-hydroxylcompounds. In one embodiment the G-type compound comprises two hydroxylgroups in contiguous position. H-type solvents are hydrocarbon compoundsor solvent which can dissolve hydrocarbons. For example, H-type solventsinclude, hydrocarbons, chlorinated hydrocarbons, alcohols, ketones, monoalcohols, and petroleum fractions such as hexane, gasoline, kerosene,dodecane, tetrolene, and the like. The H-type solvent can also be aproduct of the decarboxylation process recycled as a fraction of thehydrocarbon product. This will obviate the need of procuring additionalsolvents and hence improve overall economics of the process.

By way of further description, G-type of solvents solvate a —COONa groupof a alkali metal salt of carboxylic acid by hydrogen bonding with twodifferent oxygen atoms, whereas the hydrocarbon end of the alkali metalsalt of carboxylic acid is solvated by an H-type of solvent. For a givenG-type solvent, the solvency increases with increase of hydrocarbons inthe H-type solvent.

The table below shows some non-limiting examples of G-type and H-typesolvents:

G-type H-type ehthylene glycol isopropanol glycerine methanol1,2-dihidroxy-4-oxadodecane ethanol 2-methyl-2-propyl-1,3-propanediolbutanol 2-ethyl-1,3-hexanediol amyl alcohol2-amino-2-methyl-1,3-propanediol octanol 2,3-butanediol hexane3-amino-1,2-propanediol trichloroethane, dichloroethane 1,2-octanediolmethylene dichloride cis-1,2-cyclohexanediol chloroformrans-1,2-cyclohexanediol carbon tetrachloride cis-1,2-cyclopentanedioltetralin 1,2-pentanediol decalin 1,2-hexanediol monoglyme diglymetetraglyme acetone acetaldehydeThe solubility of various sodium salts of carboxylic acids were testedat room temperature in a magnetically stirred glass beaker using G-typesolvents, H-type solvents, and combinations of G- and H-type solvents.The following tables show solubility test results for various salts.

Salt:Sodium Oleate Solubility limit Solvent/Co-solvents Solubility g/100g Ethylene glycol ✓ 36.00 Ethylene glycol/Isopropanol (1.4:1) ✓ 57.90Ethylene glycol/Methanol (1.4:1) ✓ 31.25 Ethylene glycol/Methanol(5.55:1) ✓ 9.56 Methanol ✓ 16.60

Salt:Sodium Stearate Solubility limit Solvent/Co-solvents Solubilityg/100 g Ethanol x Ethylene glycol x Ethylene glycol/Butanol (1:1) ✓ 4.66Ethylene glycol/Isopropanol (1.4:1) ✓ 0.35 Isopropanol x Methanol xOctanol x

Salt:Sodium Palmitate Solubility limit Solvent/Co-solvents Solubilityg/100 g Acetone x Butanol x Ethanol x Ethanol/Hexane (1:1) x Ethyleneglycol x Ethylene glycol/Butanol/Isopropanol x (1:1:1) Ethyleneglycol/Butanol/Methanol (1:1:1) x Ethylene glycol/Butanol (1:1) ✓ 18.00Ethylene x glycol/Butanol/Methanol/Isopropanol (1:1:1:1) Ethyleneglycol/Ethanol (1:1) ✓ 4.66 Ethylene ✓ 2.11glycol/Ethanol/Methanol/Isopropanol (1:1:1:1) Ethyleneglycol/Isopropanol (1.4:1) x Ethylene glycol/Methanol (1:1) ✓ 5.26Ethylene glycol/Methanol/EMIBF4 (2:2:1) x Ethylene xglycol/Methanol/EMIBF4/BMIBF4 (2:2:1:1) Ethyleneglycol/Methanol/Isopropanol ✓ 5.10 (1:1:1) Hexane x Hexane/Ethyleneglycol (2:1) x Isopropanol x Methanol ✓ 0.80 Octanol x

It should be noted that although there are specific advantages of usinga divided cell, embodiments may be constructed in which the cell isundivided. This cell may be summarized as follows:

Pt∥R—COONa+CH₃ONa+CH₃OH∥Pt

The Pt electrodes may be replaced by other electrodes, as outlineherein. Also, the sodium methoxide base (CH₃ONa) may be replaced byother bases (such as hydroxide, sodium methylate, or other bases), asdesired. Likewise, the solvent, methanol (CH₃OH), may be replaced byother solvents, as desired. In this embodiment, the anode reaction is adecarboxylation reaction to form carbon dioxide and R—R. The cathodereaction is a reduction to form hydrogen gas (the H being provided bythe methanol). In other embodiments, acetate (or other carboxylic acidanions) may optionally be used. Similarly, the acidic form of the sodiumsalt may be used, provided that there is also base to convert it to asodium salt.

Although many of the examples provided herein involve the use ofmonocarboxylic acids, dicarboxylic acids or polycarboxylic acids mayalso be used. However, when using dicarboxylic acids or polycarboxylicacids, steps (in some embodiments) may be taken to avoid or reducepolymerization. This polymerization reaction is summarized below by adicarboxylic acid, but a similar reaction is possible for apolycarboxylic acid:

Since these hydrocarbon radicals have reactive sites at each end, these.R—R. radicals could then line up to polymerize:

. . . R—R.+.R—R. .R—R.+.R—R. . . .

In some embodiments, such polymerization may be desired. In otherembodiments, polymerization is not desired. Accordingly, techniques maybe employed to reduce the likelihood of polymerization (e.g., “cut off”the polymerization). This may involve, for example, forming methylradicals (CH₃.) via acetate, forming H. radicals to truncate the Rgroup. Likewise, the techniques associated with using a mixed solventsystem may also reduce such polymerization. For example, by using anonpolar solvent in combination with a polar solvent in the anolyte, theformed hydrocarbon will be pulled into the non-polar solvent quickly,thereby preventing it from polymerizing.

Various examples of the techniques described herein may be used andperformed readily. Some of these examples include:

A number of different methods may be employed to form coupled radicalproducts within the scope of the present disclosure. For example, FIG. 6shows an embodiment of a method 600 that may be used to form ahydrocarbon or a mixture of hydrocarbons. The method involves obtaining604 a quantity of biomass. The biomass may, in one embodiment, beobtained from any source, such as from algal, plant, microbes,microorganisms, and animals. Once obtained, the biomass is converted 608into at least one alkali metal salt of a fatty acid. FIG. 1 shows avariety of different methods, procedures, reactions, and steps that maybe used to convert the biomass into at least one alkali metal salt of afatty acid. Any and/or all of these steps may be used. An anolyte willthen be prepared 612. The anolyte comprises a quantity of the alkalimetal salt of the fatty acid. The methods and ingredients outlinedherein describe how this anolyte may be prepared. Optionally, an alkalimetal formate, an alkali metal acetate, and/or hydrogen gas may be added616 to the anolyte. Once prepared, the anolyte may be placed 620 in anelectrolytic cell, such as those described herein.

After placing the anolyte in the cell, the alkali metal salt of thecarboxylic acid is decarboxylated 624. This decarboxylation may involveelectrolysis and/or photolysis. Such decarboxylation forms one or moreradicals that react to form a coupled radical product such ashydrocarbon or a mixture of hydrocarbons. These hydrocarbons may then becollected, purified (as needed) and/or used in industry.

FIG. 7 is a flow diagram showing another method 700 for producing acoupled radical product. In one embodiment, the method 700 comprisesobtaining 704 an alkali metal salt of a fatty acid. As noted herein,this alkali metal salt of a fatty acid may be derived from biomass.Alternatively, this alkali metal salt of the fatty acid may be purchasedor otherwise obtained. The alkali metal salt of the fatty acid may be asodium salt. The alkali metal salt of the fatty acid may be derived fromfatty acids (such as dicarboxylic acids, monocarboxylic acids, and/orpolycarboxylic acids), esters of fatty acids, triglycerides of fattyacids, carbohydrates, fatty acid derivatives, and/or metal salts offatty acids.

An electrolytic cell will also be obtained 708. An anolyte is alsoprepared 712. The anolyte may be of the type described herein. Theanolyte comprises a quantity of the alkali metal salt of the fatty acid.A quantity of an alkali metal acetate, a quantity of hydrogen gas,and/or a quantity of an alkali metal formate may optionally be added 716to the anolyte. The anolyte may be placed 720 in the electrolytic cell.

The anolyte is electrolyzed 724 within the cell. This electrolyzingoperates to decarboxylate the alkali metal salt of the fatty acid toform alkyl radicals. These alkyl radicals react to form a hydrocarbon ora mixture of hydrocarbons. These hydrocarbons may then be collected,purified (as needed) and/or used in industry.

Further embodiments may be employed in which the anolyte includes amixture of a fatty acid (R—COOH) and an alkali metal salt of a fattyacid (R—COO—AlMet). As described above, this anolyte (including themixture of the fatty acid and the alkali metal salt of the fatty acid)is fed into a compartment (such as the anolyte compartment 208) in whichdecarboxylation will occur.

When this mixture is decarboxylated, embodiments may be designed inwhich only the alkali metal salt of the fatty acid will decarboxylateand not the fatty acid. The alkali metal salt of the fatty acid(R—COONa) is more polar than the fatty acid (R—COOH) and thus, thealkali metal salt of the fatty acid is more likely to decarboxylate atlower voltages. Thus, by selecting a lower applied voltage, embodimentsmay be constructed in which only the alkali metal salt of the fatty aciddecarboxylates and not the fatty acid.

When the alkali metal salt of the fatty acid (R—COONa) decarboxylates,it creates an alkyl radical:

In turn, this alkyl radical (R.) can extract a hydrogen radical (H.)from the fatty acid in the anolyte:

As can be seen from this reaction, a R—H hydrocarbon is obtained. Thisreaction may not create a dimer hydrocarbon product (R—R). At the sametime, the formed fatty acid radical (R—COO.) can also decarboxylateunder the applied electric potential:

This formed alkyl radical (R.) will itself react, either by reactingwith another alkyl radical (R.) to form the (dimer) hydrocarbon R—R, orby extracting a hydrogen radical from the fatty acid to create anotherfatty acid radical (RCOO.). These two reactions are summarized below:

As can be seen from these reactions, the reaction continues to productfatty acid radicals (RCOO.) as it is being consumated and these R—COO.radicals may continue to react in the manner described herein. Thisreaction is therefore characterized as a free radical “chain reaction.”This chain reaction will continue to react until the fatty acid supplyin the anolyte is exhausted, at which point the alkyl radical (R.) willreact with another alkyl radical (R.) to create the R—R hydrocarbon.Alternatively, the reaction may be quenched using other techniques.

By using a free radical chain reaction, the reaction will be naturallydriven on its own once started. An electric potential (or electriccurrent or perhaps irradiation) is needed to start (initiate) thereaction. However, once started, the voltage/current (potential orperhaps the radiation) needed to continue the reaction become smaller(or perhaps even zero). This decrease in the requiredcurrent/voltage/radiation needed to run the reaction decreases the costsassociated with conducting the reaction.

An additional application for the present embodiments may be in thefield of bio-diesel synthesis. During some currently used bio-dieselsynthesis processes, vegetable oil is reacted with methanol in thepresence of a sodium methylate catalyst in order to form the bio-dieselproduct. This bio-diesel product is a methyl ester. During thissynthesis process, there are two phases produced, namely an upper phaseand a lower phase. The “upper” phase is the non-polar phase and containsthe methyl ester (bio-diesel product). The “lower” phase is the polarphase and includes methanol, glycerol, and the products of the vegetableoil, namely, fatty acids (or sodium salts of fatty acids), and/or othersodium salts (such as sodium chloride or sodium sulfate, etc.). Thislower phase can contain, in some embodiments, nearly 20% fatty acid (byweight). In some bio-diesel synthesis processes, there is a large amountof this lower phase produced, and thus this “lower phase” material isreadily available. Accordingly, if the lower phase is obtained, it couldbe directly fed into a cell of the type that is described herein.Alternatively, the lower phase may be pre-processed through additionalreactions (such as saponification or other reactions to increase thecontent of the sodium salt of the fatty acid). This lower phase could bedecarboxylated in a cell having a NaSICON membrane, thereby producing ahydrocarbon (and more particularly a methyl ester) that is non-polar.This produced hydrocarbon/methyl ester product could be used as a new“upper phase” for further processing and/or may be the desiredbio-diesel fuel product itself. Thus in a NaSICON cell, it may bepossible to recover and/or re-use the fatty acid in the bio-dieselprocess, thereby making the process more cost-efficient andenvironmentally-friendly. This process may also remove the sodium saltsfrom the lower phase.

Non-Exclusive Examples

Below is listed some examples of embodiments described herein. Theseembodiments are not to be construed as being limiting but are exemplary.

Preparation:

Due to the changing composition of commercially available mixtures offatty acids, surrogates (mixtures of fatty acids) were used as startingmaterials for some of the reactions. Accordingly, the followingsurrogates were prepared and/or purchased:

1) sodium oleate

2) sodium oleate & sodium linoleate, and

3) sodium oleate, sodium linoleate, sodium palmitate & sodium stearate.

In some situations, the sodium salts of the fatty acid were directlypurchased and mixed to make the surrogates. In other situations, thefatty acids were purchased and converted into the corresponding sodiumsalts by a saponification reaction using 12-15% sodiummethylate/methanol.

The appropriate solvent(s) available for the reactions was firstinvestigated to determine a solvent that may effectively solubilize thefatty acids and is also highly conductive. Solvents were consideredbased upon their ability to form highly concentrated anolyte solutionswith the selected acid starting materials. Both single phase and multiphase solvent mixtures were considered. The following solvents wereconsidered based on one or more of the following factors: (1) highsolubility at low temperatures, (2) liquids at room or low temperatures,(3) low viscosity, (4) cost, and (5) ease of product separation. Basedon the above criteria, the following solvents were identified for SodiumOleate & Linoleate: (1) Methanol, and (2) Isopropanol+Ethylene glycol.For a mixture of Sodium Oleate, Linoleate, Palmitate and Stearate,appropriate solvent systems were: (1) Butanol+Ethylene glycol, (2)Methanol+Ethanol+Isopropanol+Ethylene glycol. Once these solvents hadbeen determined, anolytes were prepared by dissolving sodium fatty acidsin minimal amount of selected solvent system.

The sodium salt solutions that were prepared had low conductivity,because of the limited number of sodium ions (when compared to aconductive solution such as brine or NaOH). Therefore, a supportingelectrolyte that is electrochemically inert to the anolyte was added forsolution conductivity purposes and to achieve a low operational voltage.Tetraethylammonium tetrafluoroborate was chosen as the supportingelectrolyte based on its cost, high solubility in the solvent systems,and its large electrochemical stability window.

A two compartment micro-reactor with a small gap between theion-conducting membrane and the anode was fabricated and used in thedecarboxylation process. The small (minimal) gap was chosen to createoptimum mass transfer conditions in the anolyte compartment. A smoothplatinum anode was used where decarboxylation occurs. A 1″ diameter and1 mm thick NaSelect ion-conducting membrane (available from Ceramatec,Inc., of Utah) was used between the anode and cathode compartment. Anickel cathode was used in the cathode compartment. A 1 liter glassflask sealed with 3-holed rubber stoppers was used. The appropriateanolyte and catholyte reservoirs were prepared and connected to thesealed flask. Each reservoir was placed on a hot plate and thermocoupleswere placed in each of the reservoirs. About 300 mL of anolyte andcatholyte (15 wt. % NaOH) were used. The temperature was controlled by atemperature controller to maintain the temperature of feed solutions tothe anolyte, and catholyte at 40 to 60° C. Peristaltic pumps were usedto circulate the solutions at flow rate of 60 to 100 mL per minute(depending on the viscosity). Lab view data acquisition was used tomeasure the voltage and current. The carbon dioxide evolved from theanolyte was fed into a CO₂ IR sensor (Detcon) where the wt. % of CO₂ wasqualitatively determined.

The electrolysis reactor was operated in batch mode. Batch mode meansthat the anolyte and catholyte were re-circulated until majority of thesodium salts were converted to hydrocarbons in the anolyte and themajority of the sodium ions were transferred to the catholytecompartment via the membrane formed sodium hydroxide in the catholyte(where aqueous sodium hydroxide is concentrated). Alternatively, theelectrolysis reactor was also operated in semi-continuous mode, i.e.,the anolyte and catholyte were re-circulated until a pre-determinedamount of sodium salts starting material (e.g., 10%) was converted tohydrocarbons in the anolyte. The reactors were operated at constantcurrent densities≧50 mA/cm² to 200 mA/cm² of membrane area. A continuousprocess may be preferred for large-scale processing in which thestarting salt concentration is always maintained and the hydrocarbonproduct is continuously removed.

The hydrocarbon product from the anolyte was at times recovered using asolvent immiscible with the starting solvent mixture. Hexane andDodecane were the choices for hydrocarbon product recovery. The hexaneor dodecane phase was analyzed by GC (gas chromatography) or GC-MS (gaschromatography-mass spectrometry) analysis for the estimation ofproduct. In some cases for quantification purpose, the starting anolyteand final anolyte were submitted without extraction with hexane ordodecane.

Test #1

Decarboxylation of sodium oleate. Sodium oleate was dissolved in amethanol solvent. The purpose of this test was to determine the productconversion efficiency in a semi-continuous mode of operation. The testwas conducted at a constant current density of 200 mA/cm² until about50% of starting material was theoretically converted.

The GC profile for the reacted anolyte is shown in Table 1. Table 1shows the major peaks, name of the chemical identified, retention timein minutes, height in microvolts, area under the curve in (μV·Min) and %area under curve. The peaks at retention time at 18.65 and 27.36 aretentatively identified as sodium oleate (C18) and C34 hydrocarbon dimer.The area under the curve for C18 peak before and after the test wascompared to determine the conversion efficiency. The product conversionefficiency based on this analysis was nearly 80%.

TABLE 1 Time Area Index Name [Min] Height [mV] [mV · Min] Area % 1Methanol 1.77 24812452.2 629819 88.145 2 Acetone 1.86 639511.8 19623.42.746 3 Unknown 18.65 497370.5 49679.9 6.953 4 Unknown 27.36 252032.915407.3 2.156

ICP (inductively coupled plasma) analysis of the reacted liquid sampleshowed that 51% of the sodium was removed from the anolyte. The sodiumtransport current efficiency was determined to be 99%.

Test #2

Decarboxylation of a mixture of sodium oleate and sodium linoleate.Sodium oleate and sodium linoleate was dissolved in a methanol solvent.The purpose of the test was to determine the reactor power consumptionand to determine a current-voltage profile when the reactor was operatedin batch mode. The test was conducted at a constant current density of50 mA/cm² until a preset voltage limit of 12 volts was reached. FIG. 8shows the voltage data for test 2. The data showed a steady low voltageof 8V during much of the test and steep voltage increase during laterpart of the test, due of the depletion of sodium in the anolyte. ICPanalysis of the reacted anolyte sample showed that 87% of the sodium wasremoved from the anolyte (initial and final sodium contents from ICP are16,000 mg/L and 2,400 mg/L respectively). The sodium transport currentefficiency was determined to be 95.5% and the power consumption wasdetermined to be 0.95 kWh/kg of hydrocarbon produced (based oncalculation that every two sodium ions removed will create a molecule ofhydrocarbon). GC analysis showed the presence of fatty acid methyl esterpeaks along with hydrocarbon peaks. It appears from the data that thereis high sodium transfer (current) efficiency with low average voltage of8.54 V and low power consumption.

Test #3

Decarboxylation of a mixture of sodium oleate, sodium linoleate, sodiumpalmitate and sodium sterate. Sodium oleate, sodium linoleate, sodiumpalmitate and sodium sterate were dissolved in a four solvent mixture ofMethanol/Ethanol/Isopropanol/Ethylene Glycol. The purpose of the testwas to determine the current-voltage profile when the reactor isoperated in batch mode. The test was conducted at a constant currentdensity of 50 mA/cm² for about 18 hours. FIG. 9 shows the voltage datafor test 3. The voltage data shows a break at about the 9^(th) hour, dueto an overnight shutoff of the reactor. The data shows a steady lowvoltage of 8V during much of the test and steep voltage increase duringlater part of the test because of the exhaustion of the reactant. Thedata shows an average voltage of about 8.37 V.

Test #4:

This test used an anolyte with the same composition as in Test #2(sodium oleate and sodium linoleate dissolved in a methanol containing10% water). The purpose of this test was to determine the productconversion efficiency in a continuous mode of operation whileeliminating the formation of fatty acid esters during decarboxylationprocess. The test was conducted at a constant current density of 200mA/cm² (4 times higher than test #2 but equal to the current density oftest #1) for a short period. The Gas Chromatogram (GC) profile for thereacted anolyte showed that only hydrocarbons as the products. Thus itappears that operation at high current density may be employed, for someembodiments, to produce the hydrocarbons.

It has also been determined that the production of hydrocarbons, couldin some embodiments, be economically feasible. For example it has beenestimated that using a continuous mode processing, 1 gallon ofhydrocarbon could be made for between $0.798 to $0.232.

Accordingly, the foregoing examples indicate the following:

-   -   Conversion of sodium salts of fatty acids to >C30 hydrocarbons        was achieved;    -   Mixtures of sodium salts of fatty acids were converted to        hydrocarbons;    -   Additives were used to assist in lowering the decarboxylation        reactor voltage at high operational current densities;    -   Nearly 80% product conversion efficiency was achieved for a        sodium oleate conversion;    -   Greater than 90% product conversion efficiency was achieved for        conversion of a sodium oleate/sodium linoleate mixture (during        continuous mode operation);    -   An NaSelect ion-conducting membrane (available from Ceramatec,        Inc. of Utah) operated at near 100% sodium ion transfer        efficiency;    -   Approximately 90% of sodium ions was transferred to the        catholyte compartment to form sodium hydroxide at a low        operational voltage;    -   The power consumption was observed to be 0.95 kWh/kg of        hydrocarbon processed;    -   The selectivity for forming hydrocarbons may be improved by        operating the reactor at high current density; and    -   The presence of water may help the selectivity towards        hydrocarbon formation.

The present invention may be embodied in other specific forms withoutdeparting from its structures, methods, or other essentialcharacteristics as broadly described herein and claimed hereinafter. Thedescribed embodiments are to be considered in all respects only asillustrative, and not restrictive. The scope of the invention is,therefore, indicated by the appended claims, rather than by theforegoing description. All changes that come within the meaning andrange of equivalency of the claims are to be embraced within theirscope.

1. A method for producing a coupled radical product comprising:preparing an anolyte for use in an electrolytic cell, the electrolyticcell comprising an alkali ion conducting membrane, wherein the anolytecomprises a first solvent or mixture of solvents, a quantity of analkali metal salt of a carboxylic acid, and a quantity of a supportingelectrolyte comprising an alkali metal salt of a lower alkyl carboxylicacid; and electrochemical decarboxylating the alkali metal salt of thecarboxylic acid within the electrolytic cell, wherein theelectrochemical decarboxylating converts the alkali metal salt of thecarboxylic acid into alkyl radicals and converts the supportingelectrolyte into a lower alkyl radical or to a hydrogen radical, whereinthe alkyl radicals and the lower alkyl radical or hydrogen radical reactto form a coupled radical product, wherein the alkali metal salt of thecarboxylic acid is formed via a saponification reaction that occurswithin the electrolytic cell.
 2. A method as in claim 1, wherein thecoupled radical product comprises a mixture of different hydrocarbons.3. A method as in claim 1, wherein the electrochemical decarboxylatingthe alkali metal salt of the carboxylic acid occurs by electrolyzing theanolyte.
 4. A method as in claim 1, wherein the alkali metal comprisessodium such that the alkali metal salt of the carboxylic acid comprisesa sodium salt of the carboxylic acid and wherein the alkali ionconducting membrane comprises a NaSICON membrane, wherein the membranedivides the cell into an anolyte compartment and a catholytecompartment, the anolyte being housed within the anolyte compartment anda catholyte being housed within the catholyte compartment.
 5. A methodas in claim 1, wherein hydrogen radicals are formed by electrochemicaldecarboxylating an alkali metal formate during the electrochemicaldecarboxylating of the alkali salt of the carboxylic acid, and/orphotolysis of hydrogen gas.
 6. A method as in claim 1, wherein the firstsolvent comprises a two-phase solvent system, wherein one phase iscapable of dissolving ionic materials and the other phase is capable ofdissolving non-ionic materials.
 7. A method as in claim 1, wherein thefirst solvent or first mixture of solvents comprises methanol.
 8. Amethod as in claim 4, wherein the catholyte comprises a second solventor mixture of solvents, wherein the second solvent or mixture ofsolvents included in the catholyte and the first solvent or mixture ofsolvents included in the anolyte are different.
 9. A method as in claim4, wherein an electrochemical reaction of the catholyte produces a base.10. A method as in claim 1, wherein the supporting electrolyte is analkali metal salt of a lower alkyl carboxylic acid having from one tofive carbon atoms.